64 research outputs found
Entropic uncertainty measure for fluctuations in two-level electron-phonon models
Two-level electron-phonon systems with reflection symmetry linearly coupled
to one or two phonon modes (exciton and E Jahn-Teller model)
exhibit strong enhancement of quantum fluctuations of the phonon coordinates
and momenta due to the complex interplay of quantum fluctuations and
nonlinearities inherent to the models. We show that for the complex correlated
quantum fluctuations of the anisotropic two-level systems the Shannon entropies
of phonon coordinate and momentum and their sum yield their proper global
description. On the other hand, the variance measures of the Heisenberg
uncertainties suffer from several shortcomings to provide proper description of
the fluctuations. Wave functions, related entropies and variances were
determined by direct numerical simulations. Illustrative variational
calculations were performed to demonstrate the effect on an analytically
tractable exciton model.Comment: 14 pages, 10 figs, published in Eur.Phys.J 38 B (2004) 25-3
The Energy Density of the Quaternionic Field as Dark Energy in the Universe
In this article we describe a model of the universe consisting of a mixture
of the ordinary matter and a so-called cosmic quaternionic field. The basic
idea here consists in an attempt to interpret as the energy density
of the quaternionic field whose source is any form of energy including the
proper energy density of this field. We set the energy density of this field to
and show that the ratio of ordinary dark matter energy density
assigned to is constant during the cosmic evolution. We investigate
the interaction of the quaternionic field with the ordinary dark matter and
show that this field exerts a force on the moving dark matter which might
possible create the dark matter in the early universe. Such determined
fulfils the requirements asked from the dark energy. In this model of
the universe, the cosmical constant, the fine-tuning and the age problems might
be solved. Finally, we sketch the evolution of the universe with the cosmic
quaternionic field and show that the energy density of the cosmic quaternionic
field might be a possible candidate for the dark energy.Comment: 15 page
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